De-projecting astronomical surveys

Tue, May 10, 2016 at 1:00 pm

131 Campbell Hall

Brice Menard (JHU)

Observations of celestial objects are inherently a 2D mapping on the sphere but astrophysical studies usually require the knowledge of 3D positions. For most extragalactic sources, this estimation relies on photometric redshifts which require strong assumptions and can lead to catastrophic failures. In this talk I will show how it is possible to use clustering measurements to infer redshifts for any type of extragalactic sources. I will show how to turn this idea into a new tool for redshift estimation and show how accurate it is. I will then present applications of this "clustering-redshift" technique using various datasets at UV, optical, IR and radio wavelengths, and will show a number of surprises.